Subtraction of fractions that are horizontally arranged. Time challenge math quiz for children from 2nd to 6th grades. Math Time challenge interactive online fun game: This game is an interactive online test for children to practice their skills on fractions. Each game has multiple choice answers to problems. These games are suitable homeschool and classroom practice for children in 2nd, 3rd, 4th, 5th, 6th and 7th grades. Click start and begin practicing.